Why are the plebians so hostile toward Coriolanus?

In the opening scene of the play, one member of the angry plebian mob says of Coriolanus, "Let us kill him, and we'll have corn at our own price" (I, i., l.10). This implies that the people are hostile toward Coriolanus as a member of the Roman patrician class depriving them of basic sustenance. But there is no evidence that the lower class is starving, merely that the price of corn is high, and the people do not vent their wrath toward Menenius or any of the other rich Romans. Coriolanus makes no bones as to his opinion of the plebians, whom he calls "scabs" on the body politic. It is not the protagonist's hostility toward them that provokes the hatred of the people. It is, rather, his absolute indifference toward them. In Act II, scene ii, two officers are engaged in conversation and the second of them say: "Therefore, for Coriolanus neither to care whether they love him or hate him manifests the true knowledge he has in their disposition and out of his noble carelessness let's them plainly see 't" (ll.11-15). Coriolanus's low opinion of the plebians proves accurate. The mob is actually beneath his contempt, for as the demagogic tribunes Sicinius and Brutus plainly know, the people can be moved by the most superficial expressions of concern for their rights, rights that they do not, at bottom, have or deserve.